解方程.(1)12x+13x=34(2)17-120%x=5(3)x-12%x=2.816(4)45×14-12x=12

2025-01-18 18:15:48
推荐回答(1个)
回答1:

(1)

1
2
x+
1
3
x=
3
4

           
5
6
x=
3
4

        
5
6
6
5
=
3
4
×
6
5

              x=
9
10


(2)17-120%x=5
      17-1.2x=5
 17-1.2x+1.2x=5+1.2x
       5+1.2x=17
     5+1.2x-5=17-5
         1.2x=12   
    1.2x÷1.2=12÷1.2
            x=10    
                               
(3)x-12%x=2.816
      0.88x=2.816 
0.88x÷0.88=2.816÷0.88 
          x=3.2                                          

(4)
4
5
×
1
4
-
1
2
x=
1
20

       
1
5
-
1
2
x=
1
20

    
1
5
-
1
2
x+
1
2
x=
1
20
+
1
2
x
      
1
20
+
1
2
x=
1
5

  
1
20
+
1
2
x-
1
20
=
1
5
-
1
20

         
1
2
x=
3
20

       
1
2
x×2=
3
20
×2
            x=
3
10